benson 2009-3-25 11:56
行星環反照光下的土星風暴
An Unusually Smooth Surface on Saturn's Telesto
[img]http://i14.tinypic.com/44aokli.jpg[/img]
影像提供: Cassini Imaging Team, SSI, JPL, ESA, NASA
[color=navy]Explanation: [/color]
[color=dimgray]Imaged on the night side of Saturn by the Cassini spacecraft, these swirling storm clouds are illuminated by ringshine - sunlight reflected from the gas giant's magnificent ring system. The storm (top) was actually spotted last month by amateur astronomers as it rotated across Saturn's day side and spans about 3,500 kilometers. When the storm was on the same side of Saturn as the Cassini spacecraft, bursts of radio noise were detected, suggesting lightning discharges connected with the storm were responsible for the radio emission. While no lightning is seen directly in this Cassini image, scientists note that this storm appears along the planet's southern hemisphere storm alley in approximately the same location as Saturn's Dragon Storm, reported early last year. Though the new storm is larger and seems to be more powerful, it could well be the Dragon Storm reemerging. [/color]
[color=navy]說明:[/color]
[color=dimgray]卡西尼號太空船在土星黑夜面拍攝的夜面影像，呈現了陽光從這顆氣態巨行星壯麗環系反射的反照光所照亮之土星漩渦狀風暴雲。影像頂端的風暴系統是在上個月由業餘天文學家所發現的，它當時隨著土星自轉而移過向日面，大小約有3,500公里寬。當這個風暴和太空船同在夜面時，探測器記錄了許多電波噴訊，顯示這些電波輻射是來自風暴系統內的閃電活動。這張照片雖然沒直接記錄到閃電，科學家注意到這個風暴出現在土星南半球稱為暴風谷的區域內，大約和去年初的土星龍形暴風相同位置。雖然這個新暴風較大，威力也較強大，但它很可能是龍形暴風的再生。[/color]
[size=2]資料來源: Scientific American
Department of Physics, NCKU[/size][color=white][size=1]
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